Abstract: To optimize the preparation process of Al₂O₃-C refractories,the influence of various factors on the oxidation resistance and hydration resistance of the refractories was studied.Cylindrical samples of 50 mm×50 mm were prepared using tabular corundum,Al powder,fused zirconia corundum,activated alumina powder and graphite as the main raw materials and thermosetting phenolic resin as the binder,hydro-forming and heat treating in a carbon embedded atmosphere.The Al powder addition (6%,9% and 12%,by mass),graphite addition (5%,15% and 25%,by mass),heat treatment temperature (680,950 and 1 500 ℃) and thermal insulating time (3,6 and 9 h) were selected as the research factors,and three levels of each factor were selected for orthogonal design.The results show that:(1)the additions of Al powder and graphite are the main factors affecting the oxidation resistance,while the heat treatment temperature and thermal insulating time are the secondary factors;(2)the Al powder addition and heat treatment temperature are the main factors affecting the hydration resistance,while the graphite addition and thermal insulating time are the secondary factors;(3)comprehensively considering,the optimal process is 9% Al powder,5% graphite,heat treatment temperature of 1 500 ℃ and thermal insulating time of 6 h,and the prepared sample contains columnar Al₄O₄C,which can significantly improve the oxidation resistance and hydration resistance of the materials.

Key words: Al₂O₃-C refractories, Al₄O₄C, hydration resistance, oxidation resistance

摘要： 为了研究各因素对Al₂O₃-C耐火材料抗氧化和抗水化性能的影响,以优化其制备工艺,以板状刚玉、Al粉、电熔锆刚玉、活性氧化铝粉、鳞片石墨为主要原料,使用热固性酚醛树脂为结合剂,采用液压成型制成 50 mm×50 mm 的圆柱体试样,在埋碳气氛下对试样进行了热处理。选取Al粉加入量(加入质量分数分别为6%、9%和12%)、石墨加入量(加入质量分数分别为5%、15%和25%)、热处理温度(680、950、1 500 ℃)和保温时间(3、6、9 h)为研究因素,每个因素选取3个水平进行正交设计,分析了其对Al₂O₃-C耐火材料抗氧化和抗水化性能的影响。结果表明:1)Al粉加入量和石墨加入量为影响抗氧化性能的主要因素,而热处理温度和保温时间为次要因素;2)Al粉加入量和热处理温度是影响抗水化性能的主要因素,而石墨加入量和保温时间为次要因素;3)综合考虑,最优工艺为:Al粉加入量9%(w),石墨加入量5%(w),热处理温度1 500 ℃,保温时间 6 h,制备的试样中存在柱状的Al₄O₄C,能够显著提高材料的抗氧化和抗水化性能。

关键词: Al₂O₃-C耐火材料, Al₄O₄C, 抗水化性能, 抗氧化性能